1. Field of the Invention
This invention generally relates to a bicycle rim. More specifically, the present invention relates to a reinforced bicycle rim that has reinforcement members at the spoke openings.
2. Background Information
Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle. One component that has been extensively redesigned is the bicycle wheel. Bicycle wheels are constantly being redesigned to be strong, lightweight and more aerodynamic in design as well as to be simple to manufacture and assemble.
There are many different types of bicycle wheels, which are currently available on the market. Most bicycle wheels have a hub, a plurality of spokes and an annular rim. The hub is attached to a part of the frame of the bicycle for relative rotation. The inner ends of the spokes are coupled to the hub and extend outwardly from the hub. The annular rim is coupled to the outer ends of the spokes and has an outer portion for supporting a pneumatic tire thereon. Typically, the spokes of the bicycle wheel are thin metal wire spokes. The ends of the hub are usually provided with flanges that are used to couple the spokes to the hub. In particular, holes are provided in the hub flanges. The wire spokes are usually bent on their inner end and provided with a flange that is formed in the shape of a nail head. The inner end is supported in one of the holes in one of the hub flanges. The outer ends of the spokes typically are provided with threads for engaging spoke nipples, which secure the outer ends of the wire spokes to holes in the rim.
Recently, bicycle wheels have been designed that have utilized spokes with higher tension between the rim and the hub to provide a more rigid wheel. When the tension in the spokes becomes very high, very strong rims are required. If the rim is made thicker over its entire circumference or a steel rim is used, then the rim may become undesirable heavy. Thus, several attempts have been made to create rims that are lightweight and can accommodate high tension spokes. One example of a bicycle rim that can accommodate high tension spokes is disclosed in U.S. Pat. No. 6,283,557, assigned to Shimano, Inc. The bicycle rim of this patent uses spokes that are attached to side surfaces of the rim by using special washers. While this rim works very well, it requires special washers that are attached to the end of the spokes with spokes having a bent end. Several bicycle wheels have been developed that use straight spokes. These straight spokes are very strong and allow for higher tension to be used in the spokes. However, again, when the tension in the straight spokes becomes very high, then very strong rims are required. As a result, thicker and/or reinforced rims are needed when using straight spokes under high tension. Some of these reinforcements are welded or brazed to the rim, which can result in the physical properties of the rim being altered by the heat of the welding or brazing process. Thus, these thicker or reinforced rims are often heavy, difficult to manufacture and/or expensive to manufacture.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved reinforced rim. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.